you dont need to buy a house to be happy, but having your own place does give you a certain amount of financial security.
After x years, your mortgage is paid off - no more payments.. so in later life when perhaps your income is lower, you have no worries about finding £x a month in payments
If you keep up payments, you can't be asked to leave the property. rental leases are far more precarious.
No landlord issues - so If you want to move your friend in, you can. If you want to move 3 friends in you can. If you want a cat, you can. If you want to paint ever wall black, you can etc.... no landlord to get 'permission' from.
All these little things can offer a great feeling of satisfaction